PFI Chart A-1, Inoperative Service Engine Soon Light
SERVICE ENGINE SOON light is controlled by PCM and turns on for 2 seconds when ignition switch in turned to RUN position. When engine is cranked, SERVICE ENGINE SOON light will be off. After engine starts and ignition switch is returned to RUN position, SERVICE ENGINE SOON light will turn on for another 2 seconds.
NOTE:
Test number refers to number on diagnostic chart.
- Terminals D1, D6, D7 and A12 are PCM ground. Terminals B1 and C16 are battery positive to PCM. PCM should function with only one power and ground connection, but all should be tested.
NOTE:
Figures 9, 10, 13, 14, 17-20, 26-31, 37, 54-57, 87-96, 109-115, 117-121, 127-129, 139-142, 144, 146-149 are Courtesy of General Motors.